The lichen genus Tuckermannopsis Gyeln. (Parmeliaceae) is circumscribed. Seven species are included in the genus in the strict sense: T. americana, T. chlorophylla, T. ciliaris, T. gilva, T. microphyllica, T. orbata and T. ulophylloides. ITS rDNA sequences of the bipolar taxon T. chlorophylla do not indicate the geographical origin of the samples. Other sequence data indicate that two species previously included in the genus, T. subalpina and T. platyphylla; belong elsewhere